


confession

by sugarplumfairy



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Blow Jobs, Catholic Guilt, F/M, No betas we die like Glenn, Post-Timeskip | War Phase (Fire Emblem: Three Houses), Seteth Spoilers, Vaginal Sex, blue lions route technically, im sorry this was supposed to be really sweet but this is the closest to rough sex i'll ever write, seteth goes a little feral
Language: English
Status: Completed
Published: 2020-04-30
Updated: 2020-04-30
Packaged: 2021-03-01 22:08:53
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,314
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23924389
Author URL: https://archiveofourown.org/users/sugarplumfairy/pseuds/sugarplumfairy
Summary: Now that Byleth is clearly in it for the long haul, Seteth has some major sins to confess.
Relationships: My Unit | Byleth/Seteth
Comments: 7
Kudos: 180





	confession

**Author's Note:**

> basically this is "i did seteth's romance in the blue lions route but like. he HAD to tell byleth at some point." 
> 
> this was supposed to end with like some really sweet Signature Plum smut but it totally turned into release the beast shit sorry i just really want that dragon dad
> 
> disclaimer i havent actually played silver snow, everything i know is just from verdant wind and/or the wiki

There’s a coy smile on her lips when she closes the office door. It’s unbearable.

“ _Summoned_ to your office?” she asks, and waves the note at him. “Am I in _trouble_?”

_No, of course not,_ he wants to say. _It is not your fault, it was never your fault,_ he wants to say. _Please stop looking at me like that, like I have sold you completely on this lie,_ he wants to say.

Instead, his parched throat only manages to utter, “No.”

His heart breaks further as her smile falls. She assesses him, (and something inside him still marvels at the tactical wit behind her sharp gaze) observes his nervous fingers and his measured breaths and his troubled brow.

“What’s wrong?” Byleth asks. He watches her shoulders straighten, her mouth settle into its well-worn line. Practical, intelligent Byleth.

A thousand times. A thousand times he’s imagined this encounter, and still he doesn’t know where to start.

“We must have a very serious conversation,” Seteth says.

She looks at him again, at his slightly bowed head, at his eyes – always so sad, but somehow even more so now. A heavy feeling settles in her gut.

“Are you… breaking up with me?”

“No! No, I would never–” Seteth splutters, and pinches the bridge of his nose. It’s so typical of him that she laughs despite the situation.

“Although,” Seteth continues, “I will understand if you do not want to continue this relationship with me, after you hear what I am about to confess to you.”

She takes a moment to weigh his words but her conviction, as always, doesn’t falter.

“Tell me, Seteth. Whatever it is, I’m not afraid.”

The distance of the desk between them seems like a mile. Byleth steps up to the edge and reaches her hand out to cover his shaky one. He looks up at her and it already feels like he’s pleading for forgiveness.

“You are already aware that I bear the Crest of Cichol. The Major Crest, not a minor one,” he says. “And that Flayn – my _daughter_ , not my sister – bears the Crest of Cethleann.”

“Yes.”

Her stare is too much. It’s open and honest and it makes the weight of his lie all the more apparent. He scrambles for a way to stall the truth.

“I apologize. I should have told you this long ago. It was never the right time—”

Byleth shushes him and takes his other hand in hers.

“Seteth. Please tell me.”

His tongue feels like lead. He takes a deep breath to try and loosen it.

“I am not a descendant of Saint Cichol,” he says. “I _am_ Saint Cichol.”

Byleth blinks. Once. Twice.

Seteth forgets how to breathe.

“Wow. Okay,” she says, her face blank as always.

“‘Wow, okay?’ That is all?”

“What did you want me to say?” She sits down across from him and the mere shift of perspective, eye to eye, makes the conversation feel… normal. The weight on Seteth’s chest lifts like a spent cloud.

“Are you not angry?” he asks.

Byleth thinks. “I’m surprised. A little confused. I’m not angry.” She huffs out a shallow laugh. “I mean, I get it. There’s not really an opportune moment to go ‘Hey, by the way, I’m actually Saint Cichol.’”

Seteth finds himself laughing with her, and not because it’s funny, but because all the guilt and the fear and the nerves need an outlet.

Byleth rubs her thumb over the back of his hand as they come back to themselves.

“So what does that really mean? Just that you’re, like, a thousand years old?”

“Does that bother you?” Seteth asks. He had never thought of the age difference in that way before, but—

“No,” she says. “I think once you get past the one-hundred-year mark it doesn’t matter anymore.”

“You are taking this in remarkable stride.”

Byleth shrugs. “I mean, I went from being an above-average mercenary to being, somehow, the reincarnation of the progenitor god. There’s not much that really surprises me anymore.”

For a moment, Seteth considers telling her more than he should.

That’s Rhea’s secret to tell, not his. But he does have one more secret of his own.

“We do not have time for the entire story, but there is one other significant difference,” Seteth says.

She lets him guide her hands to the sides of his face. He leads her higher, beneath the thick curtain of his hair, and then lets her explore on her own.

He wants to melt into her cool fingers on his scalp, but she finds the edge of his ear and looks to him for confirmation. He nods.

She runs her fingers, rough from sword hilts and years of battle wounds, along the outside edge of his ears. Her brow creases as she nears the top, as she realizes what she’s meant to find.

She tucks his hair behind his ears to see for herself. She traces a finger along the pointed tip with a look of wonder.

“Just like Sothis,” she says. “Are you…?”

“No, I am not human,” Seteth says. “That might be a story for another time, but… You know of the Immaculate One, yes?”

“I’ve seen illustrations. So… you’re a dragon?”

Seteth laughs. “In essence. That is what the humans have taken to calling our kind.”

“And here I thought your fussiness over your hair was just self-obsession,” Byleth says.

“It is a little of both.” Seteth counts his blessings again as he watches her, transfixed. The worry line between her brows is once again smooth. “You are not intimidated by the fact that such a beast dwells within me?”

“I think it’s kind of hot, actually.”

Seteth flushes and tries not to roll his eyes. “I suppose I should have expected such an answer from you.”

She smiles. She _smiles._ Praise the goddess for the minor miracle of smiles.

“So, am I supposed to call you Cichol now?” she asks.

“You can call me whatever you like.”

“All right… Cichol.”

The silence grows stale.

“No, that’s weird,” Byleth says. “I’m still going to call you Seteth.”

“Like I said, you can call me whatever you like,” Seteth says.

Byleth twines their fingers together. “You know, I came here expecting this to be a booty call.”

Seteth does something between a sigh and a laugh. “Business as usual, I see.”

“Seteth.” Byleth cradles the side of his face in her hand. “I understand that you just shared something very vulnerable with me. And it doesn’t change the way I feel about you.”

“But,” he says, and he has to blink back his tears, “I lied to you for _years._ About Flayn, about who we are—”

“I want you. All of you. With all of your baggage.” She leans close and presses a light kiss to his lips. “It won’t be so heavy if we carry it together.”

He doesn’t know where the courage comes from, but he holds her closer and kisses her again. This time it’s more. It’s gratitude and atonement and all the emotions that he doesn’t have adequate words for.

And he swears, he swears to all that is holy, that if his damn desk doesn’t get out of the way he’ll break it in half himself.

Thankfully for the Garreg Mach furnishing budget, Byleth climbs up and over the desk to settle herself in his lap. When she kisses him again he holds her even closer, afraid to let her go.

She undoes the buttons of his high collar, just enough for her lips to find his throat. His head goes light as her hand reaches for his belt and she scoots his chair back to lower to her knees before him.

“By, you do not have to—”

“You’re a saint, right? Let me worship you properly.”

She works open his trousers and takes him in hand. He bites back a moan when she runs the flat of her tongue from the base of his cock up to the tip.

“Come on, Seteth,” she teases. “Let me hear you.”

He mumbles something inaudible, hiding his mouth with the back of his hand, but his words become clear when Byleth swallows him down to the root and both of his hands grasp her hair on instinct. “H-hardly appropriate—”

She comes up for air before she resumes her dive and Seteth is lost in the vice of her upper throat, in the expertise of her tongue, in the vibration of her own stifled moans.

His control slips ever so slightly, and he feels the beast he’d suppressed for centuries tug against its chains. He forces her head down and thrusts up into her, and his control breaks a little more when she quietly chokes on his cock.

“Sorry, sorry,” Seteth says, but Cichol notices the way her hand reaches down between her legs and presses against her clit through the black fabric of her shorts, how her thighs clench together to relieve the ache that must be insistent at this point.

Byleth pulls back for air, but as soon as she gets it he pushes her down onto his cock once more, revels in the wet throaty noise that she makes, watches her work herself in circles with no relief. The way she tries to swallow around him feels divine, but he wants more.

He pulls her off of him and she leans back on her haunches to gasp for breath, lips swollen and damp, cheeks flushed a deep red. She already looks wrecked, hair mussed where Seteth had tugged it, and the sight is enough to bring him back to his senses.

“Byleth—Goddess, I am so sorry,” Seteth whispers, forcing his mind into clarity. “I did not intend to harm you, we can stop if you—”

“I said I want all of you, and I meant what I said,” Byleth says. She wraps her hand around his cock once more and Seteth hisses through his teeth. “I want the good and the bad. I can handle the thing inside you, Seteth. Let it out.”

She pumps him once, twice, and he has to brace a hand on her shoulder to steady himself. It takes a great effort to speak clearly.

“If it becomes too much – if it frightens you, stop me. Promise.”

“I promise,” she says. “But it’s still you, Seteth. I could never be frightened.”

She pulls him back into a kiss, and this time when the instinct comes he doesn’t fight it.

“Up,” he says, more of a growl than a word, and her immediate compliance delights him.

He stands up with her and pins her against the edge of his desk with the weight of his body, his cock slick between them and his head just a buzz of some primal need to _fuck her, fuck her, fuck her._

A whine rises in the back of her throat and she tries to find some friction on his length. He guides her to perch on the edge of the desk, and digs his fingers deep enough to pull her shorts, tights, and panties down all in one go.

He has very little restraint left after that, so he enters her swiftly and without ceremony. Byleth claps a hand over her own mouth to stifle her cry, and bites her lip to hold back her moans once he sets a brutal pace.

Seteth leans over her, interlaces his fingers with hers to pin her hands down to his desk. _Fuck her, fuck her, fuck her._ He skims his teeth over the column of her throat, dips his tongue into the hollow of her collarbone.

And then he hears what she’s whispering.

“Seteth, Seteth, Seteth,” over and over again like a prayer.

What’s left of his mind tethers itself to that word, to the name that he’d chosen. The name that had served him well these many centuries. The name that means Garreg Mach, the name that means peace, the name that means love and Byleth and musty libraries and lance practice.

_It’s still you, Seteth._

Seteth looks up at her, lips shiny with spit and precum, eyes screwed shut in ecstasy. She feels his stare and opens her eyes, focuses on him with a blissed-out smile even as she’s pounded into the wood. She frees her hand to reach up and tuck his hair behind his ear.

_I could never be frightened._

He leans down again to leave kisses along her jaw, down the side of her neck, anything to keep him anchored here in reality as his world falls apart around him.

He’s close, and the instinct tells him to _hurry, hurry, hurry—_

Three loud knocks on his office door and they both freeze in place, startled and suddenly vulnerable.

Seteth goes cold all over, and his mind snaps back to clarity in a rush. They both hold their breath.

From the other side of the door, Gilbert clears his throat. “If you two are quite done in there, everyone has been waiting for the strategy meeting to begin.”

Seteth and Byleth exchange frantic, questioning looks, unsure if anything should – or _could_ – be said to defend their dignity. But before either can reply, Gilbert’s heavy footsteps disappear down the hallway. They wait until the sound fades completely.

“Never, in my long years, have I ever been as thoroughly mortified as I am right this moment,” Seteth says.

Byleth bursts out in laughter.

“This is no laughing matter, By. We must make ourselves presentable and—”

“He said if we’re quite done in here,” Byleth says, and tucks his hair back again where it had fallen. She brushes the back of her hand against his cheek. “I don’t know about you, but I’m not done.”

Seteth glances up at the closed door. The fact that he’s even considering it is crazy, but… he’s done crazier things for Byleth.

“Five more minutes.”


End file.
